Quick release hydraulic operator



June 14, 1932. w. .1. woons 71,863,336

QUICK RELEASE HYDRAULIC OPERATOR Filed Nov. 15, 1950 Fig.\.

Inventor: William J. Woods, by M His Attovneg.

Patented June 14, 1932 UNITED STATES PATENT OFFICE WILLIAM J. woons, 0E sonENEcrADY, NEw YORK, ASSIGNOR 1 0 GENERAL ELEcrrRIo COMPANY, A CORPORATION or NEW YORK QUICK RELEASE HYDRAULIC OPERATOR Application filed November 15, 1930. Serial No. 495,993.

My invention relates to improvements in electro-hydraulic pressure-operated devices such as described in the copending applications of Walter O. Lum, Serial No. 193,016, filed May 20, 1927, and Serial No. 415,341, filed December 19, 1929, and assigned to the same assignee as the present invention.

The device described in the appliaction of Lum referred to above comprises a fluid casing in which is mounted a piston movable in a verticaldirection. An impeller pump is mounted within the cylinder to create a pres sure on the underside of the piston to move it from a lower position to an upper position. The piston is connected to a work-engaging member. One of the difficulties encountered in devices such as describedand hereinafter referred to as an operator is the inability of the operator to instantly reset. This is due to the inertia of the rotor, of the driving motor and of the impeller and its associated parts. When the piston has reached its topmost or working position and the driving motor is deenergized to cause the piston to return to its initial position, it has been found that the inertia of the rotating rotor and impeller causes the impeller to continue to rotate for a short period of time and to continue to create a pressure on the underside of the piston, thus maintaining the piston in its raised, position until the energy ofrotation has been dissipated permitting the pressure to fall off and the piston to return to its initial position. This prevents an immediate reset of the piston which action is desirable .in certain. types of operators.

' Hence it is a principal ob ect of my invention to provide an improved type of electrohydraulic operator in which the effect of the inertia upon instant reset is eliminated as much as possible. i

In the preferred embodiment of my invention I provide a casing in the form ot a cylinder in which a piston moves, the piston being immersed in a fluid such for example as oil. The piston houses and carries therewith an impeller pump for creating a pressure differential on opposite sides of the piston to cause the piston to move within the cylinder. Attached to the piston and extending through the casing are push rods connected to a workengaging member. The impeller is driven by means of an electric motor. Connected between the electric motor and the impeller is an unlque one-way driving clutch which perm1 ts instantaneous disengagement from the driving motor when it is desired to deenergize theimpeller pump to permit the piston to return to initial position. v

In the accompanying drawing, Fig. 1 shows a cross section of the hydraulic operator in its position of rest; Fig. 2 is a detailed showing of the piston structure, and Fig. 3 is a detailed showing of the clutch mechanism.

In Fig. 1 the casing or cylinder 1 is provided with a covering or cylinder head 2 and supports an electric motor 3 which is covered by means of the cup-shaped member 4. The impeller 5 is mounted in the piston 6 which slides in the cylinder 1. When actuated, the impeller 5 receives oil at its top and bottom sides through the openings 10, 10, 9 and 8 and 8 (Fig. 2) and discharges the oil in a radial direction through the passageways 11, 11, thereby creating a pressure in the oil below the piston. Mounted upon the upper part 7 of the piston are the extensions 12, 12 which support the rods or extensons 13, 13. These extensions slide in the bearings 14, 14: each of which is provided with a slot such as 14 Clearances are provided in the cylinder head 2 to permit the extensions or rod 13, 13 to pass through the casing without touchingthe same. Tubular spacers or stops 24 and 247 are provided on rods 13 and 13 to limit the upward travel of the piston. Cross member 15 is supported by the rods-13 and 13'. This cross member in turn supports a work engaging element or eye member16.

Power is supplied to the impeller 5 by means of the splined shaft 17 which is rotatably mounted in the piston and supported by the self-aligning bearing 18.

The bearing 18 (Fig. 1) is of the self-aligning type so that should any misalignment occur at any point in the travel of the plston from its bottom to its top position, such misalignment will not cause any binding or damage to the rotating parts.

The clutch mechanism is capable of rotating the impeller in one direction only. Referring to Fig. 3, it will be seen that the lower end of the splined shaft 17 has rotatably mounted thereon the impeller member 5. The impeller member 5 is provided on the upper part of its hub with driving teeth in the form of a ratchet structure 5 as shown. Cooperating with this ratchet structure is the slideable key 5 which is slidably mounted in slot 17 provided in the splined shaft 17. The spring 17 normally maintains the key in engagement with the bottom of a tooth-shaped member of the ratchet mechanism carried in the hub of the impeller 5. lVhen the motor is rotating in one direction it positively drives the impeller 5 to create a pressure differential between opposite sides of the piston 6 to cause the piston to be raised within the cylinder. When the motor 3 is plugged or reversed the key member 5 is forced against the spring member by the inclined face of the teeth of the ratchet and slips on the tooth formation of the ratchet carried by the impeller 5, due to the rapid rotation of the splined shaft 17 and to the inertia of the impeller and oil included between the impeller blades. Thus the impeller comes immediately to rest since the oil' has large internal friction and since the driving motor is disengaged from the impeller.

Referring to Fig. 2, the details of the piston will be more clearly seen. The piston consists of two parts, a lower part 6 and an upper part 7 which carries the extensions 12, 12'. The passageways 8 and 8 which open up into the cup-shaped portion 9 on the lower side of the impeller permit the oil above the piston to pass through the piston and be expelled by means of the impeller 5 through the passageways 11. Oil from above the piston also passes through the passageways 10, 10 and comes into contact with the upper portion of the impeller 5 and is expelled through the openings 11, 11'.

The bearings 14, 14 act as wipers for the rods 13, 13.. However, oil which adheres to the rods 13 and 13 will return to the space which is above the bearings 14, 14 because of the clearance in the cover around the extensions. The oil which is there received will then return to the oil reservoir by means of the slot 14 The operation of the device is as follows: lVhen it is desired to raise the work engaging member 16, the motor 3 is energized to rotate the shaft 17 which in turn drives the impeller 5 by means of the spring actuated clutch mechanism. The liquid within the casing enters the portion of the piston 6 in which the impeller is located through the passageways 10, 10, 8, 8 and 9, as heretofore described and explained, and is discharged in aradial direction through passages 11, 11. This causes a pressure differential between opposite sides of the piston with the pressure exerting a force upon the bottom of the cylinder to cause it to be raised within the cylinder, the rate at which the piston is raised depending upon the area of the piston, the load lifted thereby, the impeller diameter and the rate of rotation of the motor. To permit the piston to instantly return to its lower position, the motor 3 is plugged or reversed. Upon reversal of the rotation of the motor 3 the clutch mechanism permits the shaft 17 to slip with respect to the impeller 5, the impeller comes to rest substantially instantaneously and the piston returns without delay to its initial position the oil passing backwards from the underside of the piston through the passageways to the upper side of the piston.

It will thus be seen that I have by a simple expedient provided a hydraulic operator in which the resetting action is immediately begun when the impeller is deenergized, the delay formerly introduced by the inertia of the motor rotor being eliminated.

It will be apparent that the invention is susceptible of being modified to meet different conditions encountered in its use and I therefore aim to cover by the appended claims all modifications within the true spirit and scope of my invention.

lVhat I claim as new and desire to secure by Letters Patent of the United States, is,-

1. An electro-hydraulic operator including a fluid casing, a piston therein biased to one position and movable in response to a change in pressure in the fluid to another position, a pressure creating impeller pump for moving said piston to said other position, a reversible electric motor for driving said pump, driving connections between said motor and pump for driving said pump in one direction only to move said piston, said driving connections permitting said pump to come immediately to rest when said motor is reversed, whereby said piston will return substantially immediately to its biased position.

2. A hydraulic operator comprising a fluid container, a piston therein biased to one position and moved by a change in pressure in the fluid, an impeller pump carried by said piston for creating a pressure differential between the two surfaces of said piston for moving the same to another position, reversible driving means for said pump and one-way operating connections between said driving means and said pump whereby after drivingsaid pump in one direction upon reversal of said driving means said pump will substantially instantly come to rest, whereby said piston will return substantially immediately to its biased position.

3. An electro-hydraulic operator including a fluid casing, a piston movable therein ating connections between said motor and pump, said connections permitting relative movement between said motor and pump to permit said pump to come immediately to rest when said motor is reversed whereby the effect of inertia of the motor on said pump is eliminated. permitting said piston to return immediately to its biased position.

4. An electro-hydraulic operator com-.

prising a fluid container, a fluid therein, a piston therein movable between two positions and biased to one of said positions and housing an impeller pump movable therewith, a reversible electric driving means for said pump, connecting means for said driving means and pump for driving said pump in one direction only to move said piston to the other position, said connections upon reversal of said electric motor driving means permitting said pump to slip with respect to said driving means whereby said pump will come substantially instantaneously to rest and said piston will return immediately to its biased position.

5. An electro-hydraulic operator comprising a fluid container, a piston immersed in the fluid in said container movable between two positions and biased to one of said positions, an impeller pump, an electric motor for driving said impeller pump, connections between said motor and said impeller pump for driving said impeller in one direction only for creating a pressure in said fluid to move said piston to the other position, said connections permitting said motor to be reversed to disengage said motor from said impeller when said piston is in said other position to prevent the inertia of said motor from effecting a continued operation of said impeller whereby upon reversal of said motor said piston will immediately start to return to its biased position.

6. An electro-hydraulic operator comprising a fluid container, a piston immersed in the fluid in said container and movable between two positions, said piston being biased to one of said positions, an impeller pump, an electric motor for driving said pump, and connections between said motor and said pump for driving said pump in one direction only for creating a pressure in the fluid to move said piston to another position, said connections including'a one-Way automatic clutch mechanism for permitting said motor to be'reversed to disengage said motor from said pump when said piston is in said other position to prevent the inertia of said motor from effecting continued operation of said] pump whereby said piston can immediately return to its biased position.

. 7. An electro-hydraulic operator including a fluid casing, a piston biased to one position and movable in response to a change of pressure therein, an impeller pump for creating a pressure to move said piston to another position, a reversible electric motor for driving said impeller pump and driving connections between said electric motor and said impeller pump including a drive shaft, a key slidable in said shaft and biased into operative engagement with said pump to drive the same in one direction only, said driving connection permitting said pump to come immediately to rest when said motor is reversed, whereby said piston can immediately return to its biased position.

8. A hydraulic operator including a fluid casing and a piston movable therein between two positions and biased to one of said posi tions, an impeller pump for creating a pressure to move said piston to the other position, a reversible motor for driving said pump, driving connections between said pump and said motor comprising a shaft on which said impeller pump is rotatably mounted, said pump being provided with driving teeth therein, a key slidably mounted in said shaft and biased into engagement with said teeth to provide a one-way drive connection between said shaft and pump, said driving connections permitting said pump to come immediately to rest when said driving motor is reversed, whereby said piston will immediately. return to its biased position.

In Witness whereof, I have hereunto set my hand this 14th day of November, 1930.

WILLIAM J. WOODS. 

